Oil sand is a sand layer or sand body having pore spaces filled with oil, often considered to be a mixture of sand, clay, water, and bitumen (i.e., hydrocarbon fluid with a gravity of 10° API or lower, such as asphalt, mineral wax, etc.). Both in-situ recovery (i.e., extraction through wells) and mining methods are used to extract oil sands. A common recovery method for oil sands is Steam-Assisted Gravity Drainage (“SAGD”) operation, which is a thermal production method that pairs a high-angle injection well (or injector) with a nearby production well (or producer) drilled along a parallel trajectory. A pair of high-angle wells, having parallel horizontal sections through the reservoir, is typically drilled with a vertical separation of about 5 meters in the parallel horizontal sections. Steam is then injected into the reservoir through the upper well. As the steam rises and expands, it heats up the bitumen or heavy oil, reducing its viscosity. Gravity forces the oil to drain into the lower well, where the oil is produced.
It is common practice in SAGD operations to perforate the entire horizontal section of the wellbore (for both the injector and producer) to let steam penetrate the reservoir. This results in a loss of steam to zones that do not contribute to production and a loss of heat to non-bitumen bearing rocks. In this case, non-productive operational expenses are incurred due to the cost of steam and ineffective operations resulting from incomplete utilization of the steam.